Fluorescent light tube adapter



March 3, 1942. A. HJMcMU LLEN I 2,274,868

FLUORESCENT LIGHT TUBE ADAPTER Filed Oct. 31, 1939 I 2 Sheets-Sheet 1 x9 59 33 as i 11m g jmm March 3 1942. A. H. McMULLE N 2,274,868

FLUORESCENT LIGHT TIIIBE ADAPTER Filed'OctQ 31, 1939 2 Sheets-She'et-Z grime/WM amaww Patented Mar. 3, 1942 UNITED STATES PATENT OFFICE isuml'loftmif'iim tl 3.2,...

2 Claims. This invention relates to showcase lighting,

I and more particularly to improved lighting equipment for store show cases.

A primary obiect of the invention is to provide an adapter or mounting element for fluorescent lighting tubes in show case reflectors, which will be convenient in design and durable and safe in use.

In the lighting of store show cases. it becamea practice in some instances to utilize incandescent electric light bulbs of the conventional pearshape Edison type. and to mount such bulbs in sockets attached to the interior of elongated concave reflectors, the bulb extending longitudinally and so received within the reflector as substantially to be concealed. while shedding its reflector-enhanced beam over the interior of the show case and the goods on display therein.

Thereafter an improved incandescent bulb of an elongated tubular design, having a substantially constant diameter. came into preferred use for show cases. This bulb. which was somewhat less in diameter than-the conventional Edison bulb, became popular and a large p portion of modern show case equipment in use was fltted with reflectors of lesser diameter than formerly to accommodate the tubular incandescent element. Both the larger pear-shaped and the lesser tubular incandescent lighting elements had screw threaded bases which were received for mounting and electrical connection in internally threaded sockets ordinarily connected directly to the power supply circuit oi the building.

Very recently fluorescent tubes have been in production for the lighting of show such fluorescent tubes being gas fllled lamps-operating on a low tension voltage which is Just below the high tension voltage on which neon lights operate. These fluot lights are an improvement over any other available lighting for show cases; among other reasons, because the light produced is a true or daylight beam. This new 7 connected through a transformer to the current supply. Instead of the spirally ded w these fluorescent tubes have terminals at each end. each terminal having two prongs. For connection in the circuit it is requisite that suitable connections be provided to enable each prong at the ends-of the fluorescent tube to be connected to the supply beyond the transformer.

Although new reflectors complete with appro It is another object of the invention to provide an adapter which will include simple and inexpensive provision for conveniently mounting fluorescent tube lamps'in reflectors oflarge or smaller concave radius.

The above and additional objects and advantages of the invention will be apparent from a consideration of the following detailed descripetion, read in connection with the accompanying drawings forming a part thereof, wherein I Fig. 1 is a fragmentary. perspective forward looking view of the interior of a conventional glass show case of the type used in department stores, said view being taken from the backs! the case and looking toward the front of the top thereof.

Fig. 2 is an enlarged diagrammatic view of a reflector oi the elongated concave type carrying adapters in embodiment of the invention. and indicat a conventional circuit arrangemen for supplying the lamps. v

Fig. 3 is a front view of the adapter for use in one present standard type reflector, such as the T40 type.

s is an end view of the adapter shown in Fig. 3.

5 is a rear view of the adapter of Fig.3. fitted in the reflector. I

. 6 is a front view of the adapter for use in ther and smaller type reflector, such as the T-Bifi type.

. 7 is an end view of the adapter shown in I 10 is a front view of a fluorescent light whichcharacterizm the incandescent type lamp, 5B tube extractor member.

.gas.

matic'switch, both designated by transformer Fig. 11 is a sectional view taken on the line of Fig. 3.

Fig. 12 is a front view of the adapter of Fig. 3 showing an insulator cover in place.

Fig. 13 is a side view of the insulator cover of F18. 12. 7

Fig. 14 is a sectional view on the line |4-|4 01 Fig. 12.

Referring to the drawings wherein similar parts are indicated by identical reference numerals, a conventional department store show case is of the rectangular type having a flat plate glass top 2|, a, plate glass front 22, and,

at each end, a plate glass end 24. These several liner or mirror element 29. Supported in the concavity of frame 28 is a fluorescent lamp Iii consisting of a gas filled glass tube carried in opposite adapters 32-32 by a connector 33 fixed to the lamp 30 and carrying two prongs 36-35 at each end of the fluorescent lamp.

The cathodes oi fluorescent lamp 30 have to be heated by the electrical current before the arc will strike or establish its path through the This requires a choke coil and an auto- 36, (Fig. 2) in each individual lamp circuit. Transformer 36, which may for convenience be carried on the floor of the show case, serves to disconnect the heating current when the arc is established, hence a four-wire hook up between lamp 30 and transformer 36 is shown. As presented, the circuit includes left end conductors 31a and 37b, and right end conductors 88a and 38b communicating with prongs B t-3t on the corresponding ends of lamp tube 39. The circuit is completed to any conventional power supply 40.

An important feature of the present invention consists of the design of adapters 82. Said adapters include an inner body 4| formed of insulating material such as porcelain, Bakelite, rubber, or thermoplastic material, and has a front 42 and back 44. Its curved exterior portion45 is preferably shaped to correspond with the concave curvature of the reflector frame and is finished with a guiding fin 48 at each side for reception in inturned flanges 48 at opposite edges of the reflector frame. Spaced recesses 49-49 infront 42 receive prongs 34-44 and are deflned by shoulders 5050 each supporting a spring contact 52 extending into the recess '49 Fluorescent lamps are described for size to the trade with respect to their. diameteras well as tubular style, while the diameter in eighths of an inch is expressed numerically. Thus, T-fiy would mean to anyone skilled in the art a tubular element approximately H of an inch in diameter.

From the foregoing it will be observed that when it is desired to install a fluorescent lamp II in one of the smaller conventional reflectors, such as that known in the trade as type T-6Vg, the assembly indicated in Fig. 8 will obtain. Therein, the body 4| forms a complete adapter which may be. adjusted slidabiy longitudinally of said smaller reflector frame to proper position with respect to the length of lamp 30. The lamp may then be connected by inserting prongs 34 in recesses 48, thereby establishing electrical contact for the left end of the lamp with spring contacts I! and electrically interconnected conductors 31a and 31b. These conductors lead along the inner surface of the reflector being accommodated in lateral recesses 58. Fixing of the adapter in position is then attained simply by tightening screw 64 to bind clamp 8| upon the flanged edge 48 of the reflector frame. When the right hand end of lamp tube 30 is connected in a right hand adapter of the type shown in Figs. 6 m8 and in electrical communication with right end conductors 38a and 38b the lighting installation for .such a smaller sized reflector is complete.

89 for snugly receiving body 4|, being characterized by opposite locking shoulders. IO-I0 for closing the lateral recesses 58 of body 4|. Enlargernent shell 68 has an outer convex surface shaped substantially to coincide with the inner concave surface of said larger type reflector frame and is formed with opposite lateral recesses 13-13 for retaining conductors flat against said reflector.

for making contact with prong 34. Lug portions 53 on contacts 52 lie in a top recess 54 for receiving conductors, such as conductors 31a and gagement with the flanges 4a of the reflector frame. Clamping member 6| has a center hole 63 for a retaining screw 64 which may be tightened for assembly in threaded recesses v65 in body-4|.

For fixing enlargement'shell 68 on body 4| the shell has. opposite screw threaded recesses'ld communicating with screw threaded recesses 18 on body 4| through which extend screws 18 which may be readily tightened to form a rigid assembly functioning as an adapter unit. An elongated clamping member 18 has terminal hooks IQ for locking engagement with edge flanges 48 of said larger 'type reflector frame. Clamping member 18 has a center hole for attaching screws 84. Opposite apertures 82 extend transversely in enlargement shells 68 for accommodating the conductors to be attached to screw binding posts 56-56 therein.

For a finished assembly when desired a cover plate OI, see Figs. 12 to 14, may be used, said-cover plate fltting over the front of inner body 4| and being attached by a screw 84. This cover plate is characterized by spaced notches CHI for reception of prongs 34-34.

As a further finishing implement a separator plate ll, see Fig. 10, may be employed. This separator plate corresponds in circumference generally tofluorescent lamp.- and hasspaced apertures "-88 for receiving prongs 34-44. An

integral ear '9 depends from the lighting fixture and may be manually grasped to assist in extracting the tube from the adapter when desired.

From the foregoing it will be observed that the adapters presented may be utilized to at either the larger or smaller conventional styles of reflectors and being readily adjustable longitudinally with respect to the frames will enable in of tubular fluorescent lamps What I claim is:

1. An adapter for fluorescent tube lamps comprising coplaner interfltting outer-and inner bodies of insulating material, the inner body having a recess for receiving fluorescent tube connector prongs, spring contacts mounted on the inner bodyiand extending in said recess, terminal posts in the inner insulating body connected to said spring contacts, communicating apertures in said inner and outer insulating bodies for conductors connectible to said. posts, a recess at the exterior oi said outer insulating body 'i'or'reconvenient, safe and economical mounting thereand housing spring contacts fixed to the body;

such body also being shapedto include a peripheral-recess spaced from said first mentioned re-- cess, conductor-end terminal posts in said peripherai recess and connected to said spring contacts, said body also having a lateral recessat each end ofsaid peripheral recess for receiving conductors-in nesting relationship therewithin, a.

clamping element and means on said relatively flat portion between said flns for retaining said clamping element.

ALVA H. McMULLEN. 

